Are there official rules when it come to maintaining gardens ? What to do with excessively picky /threatening landlord ?

Sorry for the long post/vent. Looking for outside point of views, I am seeking legal advice (legal insurance) in parallel. For context, I was born here and my ancestry too, as far as records go, so this is not a cultural thing, at least not to the extent that it could be if we were from a very different country/culture.

So we’ve been renting that 25 yo house for years directly with the owner, no 3rd party.

Since the beginning, he’s been extremely picky on the smallest thing related to maintaining the outside of the house, things like commenting on how the grass close to the tiles was not cut far enough, the tiles not being clean enough (they’re very light soft pink tiles that show the most minute piece of dirt or moss, and yes I’m not cleaning them every two weeks) and stupid comments like how we have to use the karcher on the natural rock wall (which looks something like thisthese things age naturally, what would you "clean" on this ?). He’s also been passing by, I guess, somewhat frequently, because he would call or send emails when the grass cutting was a few days to a week late. Admittedly, we haven’t always been "perfect" when it comes to maintaining the lawn, but I still feel the guy has made excessive demands and been on our ass way too much.

Recently we’ve been away on holiday, and he apparently passed by, entered the outside of the property without notifying us (I will send him a stark letter on that point), and immediately called us, being angry and aggressive, about the state of the exteriors including some "objects" that were "abandonned" around the house (I mean we live there, we have 3 kids, this is not going to look like a postal card non-stop). He then sent us a "formal notice" (official notice) detailing corrective actions within 3 days 6PM (today) of us returning from holiday, lest he will mandate a company to do the work at our expense.

I did most, if not all, of the work after getting back from work this week. The guy popped up unannounced by our house today a 3PM, with only my wife present, she still received him. Toured the outside of the house and went on pretending nothing was ok : (cleaned yesterday) tiles not cleaned, (cut) lawn with too much weeds, found new things (not mentioned in letter or previous call) like an old fruit tree at the back of the house that was not giving fruits (our contracts says we need to cut the tree every two years, which we do, I don’t really care if it doesn’t give anything), and then said to my wife he was actually considering canceling the lease (I mean, fucking do it or don’t, but don’t go throwing empty threats).

Anyway… I know I have the means to prolong the lease for a while in a situation like this (again, I’m seeking legal advice to prepare for this). What do you guys think of this situation ?

• Am I being unreasonable?
• I wasn’t able to find any legal document on "lawn/terrace/house exterior maintenance standards" yet the guy keeps saying it has to be "within the norm"is there such a thing or is that "his" norm ?

Thanks for reading !